The state of the art in fabrication of arbitrary three-dimensional objects is fused deposition modeling (FDM) in which tiny deposits of plastic analogous to a pixel in a three-dimensional model are deposited individually to build a desired object from the ground up. Among the problems facing FDM are speed and cost. Because each subsequent deposit fuses to the underlying previously deposited plastic, the size of the deposit and the temperature control required to effect the fusing is strictly limited. As a result, very small amounts of plastic are deposited with each deposition and if the temperature is not precisely controlled, failure along corresponding knit line is manifestly likely. Moreover, because of the small amount of each deposit, the other constraints of controlling the system during fabrication, the time required to produce even a relatively simple object is measured in hours.
Among the additional problems includes the need to insure desiccation of the plastic supply as moisture in the supply further causes the risk of failure of proper knit during fusing. Also, because of the small amount of plastic deposited any overhang cantilevered portion of the object must be supported by a sacrificial material that is laid down during the fabrication process and then dissolved away post-fabrication. The sacrificial material requirement increases the cost and time required to fabricate any particular object. Typically, both the sacrificial material and the build plastic are provided as a spool often costing hundreds of dollars for a relatively small volume of plastic. Moreover, if there is insufficient plastic remaining on the spool to complete a desired build, the spool must be removed and replaced and it is difficult to change spools mid-process or reuse a partially consumed spool. This further increases the cost associated with FDM.
A faster lower cost system with higher reliability is desirable.